<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    .box {
      /* border + padding + content */
      box-sizing: border-box;
      width: 400px;
      height: 200px;
      background-color: cadetblue;
      border: 2px solid #000;
      padding: 50px;
    }

    .box-p {
      width: 400px;
      height: 200px;
      background-color: rgb(151, 114, 20);
      border: 2px solid #000;
      padding: 50px;
    }

    .box-pl {
      width: 400px;
      height: 200px;
      background-color: rgb(98, 29, 216);
      border: 2px solid #000;
      padding-left: 50px;
      position: relative;
    }

    p {
      position: absolute;
      left: 10%;
      top: 20%;
      color: aliceblue;
    }
  </style>
</head>

<body style="display: flex;">
  <div class="box">

  </div>
  <div class="box-p">

  </div>
  <div class="box-pl">
    <p>我的测试</p>
  </div>
</body>

</html>